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Related papers: Simulation-based inference from the Lyman-alpha fo…

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Radiation pressure from Lyman-$\alpha$ (Ly$\alpha$) scattering is a potentially dominant form of early stellar feedback, capable of injecting up to $\sim 100 \, \times$ more momentum into the interstellar medium (ISM) than UV continuum…

Astrophysics of Galaxies · Physics 2025-01-10 Olof Nebrin , Aaron Smith , Kevin Lorinc , Johan Hörnquist , Åsa Larson , Garrelt Mellema , Sambit K. Giri

We train neural networks to perform likelihood-free inference from $(25\,h^{-1}{\rm Mpc})^2$ 2D maps containing the total mass surface density from thousands of hydrodynamic simulations of the CAMELS project. We show that the networks can…

The one-dimensional flux power spectrum (P1D) of the Lyman-$\alpha$ forest probes small-scale structure in the intergalactic medium (IGM) and is therefore sensitive to a variety of cosmological and astrophysical parameters. These include…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-22 Meagan Herbold , Naim Göksel Karaçaylı , Paul Martini

As the next generation of large galaxy surveys come online, it is becoming increasingly important to develop and understand the machine learning tools that analyze big astronomical data. Neural networks are powerful and capable of probing…

We study the evolution with redshift of the number density of Ly$\alpha$ clouds in a CDM model using numerical simulations including photo-ionization and cooling of the baryonic component. The photo-ionizing flux is consistently taken as…

Astrophysics · Physics 2019-08-17 Jan P. Mücket , Patrick Petitjean , Ronald E. Kates , Rüdiger Riediger

The density and temperature properties of the intergalactic medium (IGM) reflect the heating and ionization history during cosmological structure formation, and are primarily probed by the Lyman-alpha forest of neutral hydrogen absorption…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 Bruno Villasenor , Brant Robertson , Piero Madau , Evan Schneider

We measure the effect of high column density absorbing systems of neutral hydrogen (HI) on the one-dimensional (1D) Lyman-alpha forest flux power spectrum using cosmological hydrodynamical simulations from the Illustris project. High column…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-10 Keir K. Rogers , Simeon Bird , Hiranya V. Peiris , Andrew Pontzen , Andreu Font-Ribera , Boris Leistedt

We derive an effective field theory (EFT) for cosmological Lyman alpha forest fluctuations valid for the power spectrum at the one-loop order. The ``bottom-up'' EFT expansion at the level of the transmitted flux is identical to the…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-04 Mikhail M. Ivanov

The impact of cosmic reionization on the Ly$\alpha$ forest power spectrum has recently been shown to be significant even at low redshifts ($z \sim 2$). This memory of reionization survives cosmological time scales because high-entropy…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-14 Paulo Montero-Camacho , Yi Mao

Small-scale correlations measured in the Lyman-$\alpha$ (Ly$\alpha$) forest encode information about the intergalactic medium and the primordial matter power spectrum. In this article, we present and implement a simple method to measure the…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-27 Marie Lynn Abdul-Karim , Eric Armengaud , Guillaume Mention , Solène Chabanier , Corentin Ravoux , Zarija Lukić

The hyperfine structure absorption lines of neutral hydrogen in spectra of high-redshift radio sources, known collectively as the 21-cm forest, have been demonstrated as a sensitive probe to the small-scale structures governed by the dark…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-03 Tian-Yang Sun , Yue Shao , Yichao Li , Yidong Xu , He Wang , Xin Zhang

Models for structure formation attempt to predict the power spectrum of density perturbations in the present universe from the initial power spectrum and the nature of dark matter. Observational constraints on the power spectrum at…

Astrophysics · Physics 2007-05-23 K. Subramanian , T. Padmanabhan

In recent years, a remarkably simple physical picture of the Lyman-alpha forest has emerged, which allows detailed predictions to be made and turns the forest into a powerful probe of cosmology. We point out ways in which such a picture can…

Astrophysics · Physics 2007-05-23 Lam Hui

The highly anisotropic nature of the Lyman-alpha (Ly$\alpha$) forest data introduces a complex survey window function that complicates the measurement of the three-dimensional power spectrum ($P_{\mathrm{3D}}$). In this paper, we present…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-19 N. G. Karaçaylı , C. M. Hirata

The 21 cm signal contains a wealth of information about the formation of the first stars and the reionization of the intergalactic medium during the Cosmic Dawn (CD) and Epoch of Reionization (EoR). The timing of these important milestones…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-15 Nadia Cooper , Carina Norregaard , Romain Meriot , Jonathan R. Pritchard

This is the second paper in a series whose aim is to predict the power spectrum of intensity and polarized intensity from cosmic reionization fronts. After building the analytic models for intensity and polarized intensity calculations in…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-31 Emily Koivu , Heyang Long , Yuanyuan Yang , Christopher M. Hirata

We reanalyse the spectra used by D.-E. Liebscher (no relation) et al with the same goal -- determining the cosmological parameters -- and basically the same assumptions but with a different statistical method, which does not rely on binning…

Astrophysics · Physics 2007-05-23 Thomas Liebscher , Rainer Kayser , Phillip Helbig

The Ly-$\alpha$ forest 1D flux power spectrum is a powerful probe of several cosmological parameters. Assuming a $\Lambda$CDM cosmology including massive neutrinos, we find that the latest SDSS DR14 BOSS and eBOSS Ly-$\alpha$ forest data is…

One of the major science goals over the coming decade is to test fundamental physics with probes of the cosmic large-scale structure out to high redshift. Here we present a fully Bayesian approach to infer the three-dimensional cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-09 Natalia Porqueres , Jens Jasche , Guilhem Lavaux , Torsten Enßlin

The Lyman-alpha (Ly$\alpha$) forest at $z \sim 5$ offers a primary probe to constrain the history of the Epoch of Reionization (EoR), retaining thermal and ionization signatures imprinted by the reionization process. In this work, we…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-18 Diego González-Hernández , Caitlin Doughty , Molly Wolfson , Joseph F. Hennawi , Zhenyu Jin